WO2018123167A1

WO2018123167A1 - Developer cartridge

Info

Publication number: WO2018123167A1
Application number: PCT/JP2017/034283
Authority: WO
Inventors: 板橋　奈緒
Original assignee: ブラザー工業株式会社
Priority date: 2016-12-28
Filing date: 2017-09-22
Publication date: 2018-07-05
Also published as: US20180181022A1; JP6711268B2; JP2018109655A; US10042282B2; USRE49689E1; CN108255033B; CN108255033A; CN114942576A

Abstract

The purpose of the present invention is to disengage a drive gear and a gear other than a rotating gear from each other. A developer cartridge 1, provided with: a casing 11 capable of containing a toner in the interior; a developing roller 12 extending in the axial direction; a developing electrode 20 electrically connected to the developing roller 12; a rack gear 50 that engages with a gear (agitator gear 31), the rack gear 50 having a protrusion (53, 54); and a cam 70 capable of moving from a first position to a second position set further away from the casing 11 than the first position in the axial direction. The cam 70 has: a first cam surface 73A, which comes into contact with the protrusion at the first position; and a second cam surface 76A, which moves while being in contact with the developing electrode 20 when the cam 70 moves from the first position to the second position, and thereby moves the developing electrode 20 away from the cam 70.

Description

Developer cartridge

The present invention relates to a developing cartridge provided with a developing roller.

2. Description of the Related Art Conventionally, a developer cartridge having a detection protrusion for moving an actuator disposed in a main body housing of an image forming apparatus is known (see Patent Document 1). Specifically, in this technique, the detection protrusion has a gear and can rotate around the shaft, and the actuator is operated by pressing the actuator during the rotation. The gear has a missing tooth portion. When the chipped portion and the driving gear that transmits the driving force to the gear face each other, the gear and the driving gear are disengaged. Thereby, rotation of a gear stops. When the rotation of the gear stops, the rotation of the detection projection also stops.

JP 2013-54053 A

Incidentally, there has been a demand for a configuration in which the drive gear is disengaged from a gear other than the rotating gear in the developing cartridge.

Therefore, an object of the present invention is to provide a developing cartridge that can disengage the gear other than the rotating gear and the driving gear.

In order to solve the above-described problems, a developing cartridge according to the present invention includes a housing that can accommodate toner therein, and a developing roller that is rotatable about a first shaft that extends in the axial direction, and is positioned at one end of the housing. A developing roller electrically connected to the developing roller, a gear rotatable about a second axis along the first axis, and a rack gear meshing with the gear, from one end of the housing A rack gear that is movable in a direction toward the other end opposite to the one end, and a rack gear having a protrusion, and a second position that is farther from the housing than the first position in the axial direction from the first position. A movable cam.
The cam is a first cam surface in contact with the protrusion at the first position, and the rack gear moves in a direction from the one end toward the other end while being in contact with the protrusion. A first cam surface that moves toward the second position; and when the cam moves from the first position to the second position, the first cam surface moves in contact with the developing electrode, thereby moving the rack gear and A second cam surface that moves the developing electrode in a direction away from the cam in a direction different from a cam moving direction.

According to this configuration, the rack gear and the gear can be disengaged by moving the rack gear in a direction from one end of the housing toward the other end.

In addition, the developing cartridge may include a spring for electrically connecting the developing electrode and the developing roller.

The developing cartridge includes a bearing for supporting the developing roller, wherein one end of the spring is in contact with the developing electrode, and the other end opposite to the one end of the spring is in contact with the bearing. Also good.

Further, the spring may be shorter than a natural length in a state where one end of the spring is in contact with the developing electrode and the other end of the spring is in contact with the bearing.

Further, the bearing may be formed of a conductive resin.

Further, the developing electrode may be formed of a conductive resin.

The first cam surface includes a first end portion and a second end portion located farther from the housing than the first end portion in the axial direction, and the first cam surface May be inclined so that the first end portion is located downstream of the second end portion in the movement direction of the rack gear.

The cam is a third cam surface disposed downstream of the first cam surface in the movement direction of the rack gear, and a third contact with the protrusion when the cam is located at the second position. The third cam surface may move the cam from the second position toward the first position by moving the rack gear while being in contact with the protrusion.

The third cam surface includes a third end portion and a fourth end portion that is located farther from the housing than the third end portion in the axial direction, and the third cam surface May be inclined so that the fourth end portion is located downstream of the third end portion in the movement direction of the rack gear.

Further, the first cam surface may be disposed at a position different from the third cam surface in the moving direction of the cam.

The developing cartridge includes an agitator that stirs the toner inside the housing, and an agitator gear that is supported on an end of the agitator and is rotatable together with the agitator. The agitator gear is There may be.

Further, the developing cartridge may have a coupling disposed on the opposite side of the developing electrode with the housing interposed therebetween.

Further, the developing electrode may have a fourth cam surface that contacts the second cam surface and extends along the second cam surface.

The rack gear has a plate-like main body portion extending in the movement direction of the rack gear, and a plurality of gear teeth meshing with the gear, and the plurality of gear teeth and the protrusion protrude from the main body portion. The rack gears may be arranged at different positions in the moving direction.

Further, the protrusion may be arranged at a position different from the plurality of gear teeth in the axial direction.

The second cam surface has a fifth end portion and a sixth end portion that is farther from the housing than the fifth end portion in the axial direction, and the fifth cam surface extends from the sixth end portion to the fifth end portion. You may incline so that it may protrude toward the said developing electrode as it goes to an edge part.

The developing cartridge according to the present invention includes a housing that contains toner therein, a developing roller that is rotatable about a first shaft that extends in the axial direction, the developing roller positioned at one end of the housing, A gear that is rotatable about a second shaft extending in the axial direction, a developing electrode that is electrically connected to the developing roller, and a rack gear that is movable in a direction from the one end toward the other end opposite to the one end. A rack gear meshing with the gear and movable in a direction from the one end toward the other end as the gear rotates, a rack gear having a protrusion, and a cover covering at least a part of the rack gear, A cover having an opening exposing the developing electrode; a first position; and a cam movable to a second position farther from the housing in the axial direction than the first position. .
The cam is a first cam surface having a first end and a second end farther from the housing than the first end in the axial direction, the first end being the first end. A first cam surface that is inclined so as to be located downstream of the two end portions in the movement direction of the protrusion, and is engaged with the protrusion and is outside the movement locus of the protrusion from the first position. A first cam surface movable to a position and a second cam surface movable together with the first cam surface, wherein the first cam surface is disposed at a position farther from the housing than the first cam surface in the axial direction. A second cam surface that is movable while being in contact with the developing electrode, the fifth end portion being farther from the housing than the fifth end portion in the axial direction. A second cam surface having six ends, wherein the front surface is directed from the sixth end toward the fifth end. Having a second cam surface inclined so as to protrude toward the opening.

According to this structure, the rack gear can be disengaged from the gear by moving in the direction from one end of the housing to the other end.

The cam is a third cam surface disposed downstream of the first cam surface in the movement direction of the rack gear, and the cam is on a movement locus of the protrusion when the cam is located at the second position. A third cam surface disposed; the third cam surface being a third end; and a fourth end located farther from the housing than the third end in the axial direction; The third cam surface may be inclined such that the fourth end portion is located downstream of the third end portion in the movement direction of the rack gear.

The developing cartridge according to the present invention includes a housing that contains toner therein, a developing roller that is rotatable about a first shaft that extends in the axial direction, the developing roller positioned at one end of the housing, A gear that is rotatable about a second axis along the axial direction, a rack gear that meshes with the gear, a rack gear that is movable in a direction from one end of the housing toward the other end opposite to the one end, and a first position From the first position to the second position, the cam having a protrusion, and the cam from the first position to the second position. A biasing spring, a cover having an opening, a developing electrode electrically connected to the developing roller, the developing electrode being movable together with the cam, a fifth end portion, and the axial direction In the above A second cam surface having a sixth end portion that is farther from the housing than the end portion, and is inclined so as to protrude toward the opening from the sixth end portion toward the fifth end portion. A developing electrode having a second cam surface.
The rack gear includes a first holding surface that contacts the protrusion and holds the cam in the first position, and a second holding surface that contacts the protrusion and holds the cam in the second position.

Further, the developing electrode may be formed integrally with the spring.

According to the present invention, it is possible to disengage the drive gear from a gear other than the rotating gear.

FIG. 2 is a perspective view of the developing cartridge according to the first embodiment viewed from one end side in the axial direction. FIG. 3 is a perspective view of the developing cartridge as viewed from the other end side in the axial direction. FIG. 3 is an exploded perspective view showing components on the other end side of the developing cartridge. It is the perspective view which looked at the rack gear from the rack gear part side. It is a disassembled perspective view which shows a gear cover and its internal components. It is a perspective view which shows a cam. FIG. 3 is a perspective view showing a structure on the other end side of the developing cartridge with a gear cover removed. FIG. 5 is a cross-sectional view of the rack gear and cam engaging portions cut along a plane perpendicular to the vertical direction, and is a cross-sectional view (a) to (d) showing the operation of the rack gear and cam. FIG. 3 is a cross-sectional view of a rack gear, a cam, and a development electrode cut along a plane orthogonal to a direction from one end to the other end of the housing, and is a cross-sectional view showing the operation of the rack gear, the cam, and the development electrode. It is. FIG. 10 is a perspective view showing a structure on the other end side of the developing cartridge according to the second embodiment with a gear cover removed. It is the perspective view which shows each component which concerns on 2nd Embodiment, Comprising: The exploded perspective view (a) which shows a gear cover and its internal components, The perspective view (b) which looked at the rack gear from the rack gear part side. FIG. 10 is a cross-sectional view (a) to (c) showing the operation of the rack gear and the cam, wherein the engagement portion between the rack gear and the cam according to the second embodiment is cut by a plane orthogonal to the vertical direction. It is sectional drawing which cut | disconnected the rack gear, cam, and spring electrode which concern on 2nd Embodiment by the surface orthogonal to, Comprising: It is sectional drawing (a), (b) which shows operation | movement of a rack gear, a cam, and a spring electrode.

[First Embodiment]
Next, a first embodiment of the present invention will be described in detail with reference to the drawings as appropriate.
As shown in FIG. 1, the developing cartridge 1 mainly includes a housing 11, a developing roller 12, a supply roller 15 (see FIG. 3), an agitator 14, and a coupling 13. The housing 11 contains toner therein. In the following description, the axial direction of the developing roller 12 is also simply referred to as “axial direction”.

The developing roller 12 is a roller that supplies toner to an electrostatic latent image formed on a photoreceptor (not shown). The developing roller 12 is rotatable about a first axis X1 extending in the axial direction. The developing roller 12 has a shaft 12A extending in the axial direction. The developing roller 12 is located at one end E10 of the housing 11 in a direction from the shaft 12A toward a shaft 14A of an agitator 14 described later.

The supply roller 15 is a roller that supplies toner to the developing roller 12. The agitator 14 is a member for stirring the toner inside the housing 11.

The coupling 13 is a member that receives a driving force from the outside. Specifically, an input member that can be moved forward and backward provided in a main body housing of an image forming apparatus (not shown) moves forward into the coupling 13 and engages with the coupling 13 in the rotational direction. A driving force is input to the coupling 13. The driving force input to the coupling 13 is transmitted to the developing roller 12 through a gear mechanism (not shown) and is also transmitted to the supply roller 15 and the agitator 14.

The coupling 13 is provided on one end side of the casing 11 in the axial direction. In other words, the coupling 13 is disposed on the opposite side of the developing electrode 20 (see FIG. 2), which will be described later, across the housing 11. That is, the coupling 13 is provided on the side wall opposite to the side wall 11A (see FIG. 3) where the developing electrode 20 of the housing 11 is disposed.

As shown in FIG. 2, a developing electrode 20 for moving an actuator AC provided in the main body casing is provided on the other end side in the axial direction of the casing 11. The actuator AC is rotatably provided in the main body casing. The actuator AC is made of a conductive member. The main body housing includes a power supply unit (not shown) that supplies power to the actuator AC, and an optical sensor (not shown) for detecting the rotation of the actuator AC.

The developing electrode 20 lifts the actuator AC, more specifically, an orthogonal direction orthogonal to the axial direction by transmitting the driving force input to the coupling 13 via a gear mechanism, an agitator 14 (see FIG. 1), or the like. Move in the direction. That is, the driving force input to the coupling 13 is transmitted from one end side in the axial direction of the housing 11 to the other end side by the shaft 14 A of the agitator 14.

As shown in FIG. 3, the housing 11 has an agitator gear 31 as an example of a gear, a bearing 40, a rack gear 50, and an example of a cover on the other end side in the axial direction, in addition to the developing electrode 20 described above. The gear cover 60 is provided. The casing 11, the agitator gear 31, the rack gear 50, and the gear cover 60 are made of non-conductive resin.

The developing electrode 20 and the bearing 40 are made of a conductive material. Specifically, the developing electrode 20 and the bearing 40 are made of a conductive resin. The conductive resin is, for example, a polyacetal resin containing carbon powder.

The agitator gear 31 is supported on the other end of the shaft 14A of the agitator 14. The agitator gear 31 is rotatable about a second axis X2 along the first axis X1. The agitator gear 31 rotates together with the shaft 14 A of the agitator 14. That is, the agitator gear 31 rotates together with the developing roller 12 by the driving force input to the coupling 13.

The bearing 40 is a member for rotatably supporting the shaft 12A of the developing roller 12 and the shaft 15A of the supply roller 15. The bearing 40 includes a plate-like portion 41, a first bearing portion 42, a second bearing portion 43, and two first guide portions 44.

The plate-like portion 41 is a plate-like portion extending in the direction from the shaft 12A toward the shaft 14A. Specifically, the plate-like portion 41 extends from the shaft 12 A of the developing roller 12 toward the agitator gear 31. The plate-like portion 41 is disposed between the side wall 11A on the other axial end side of the housing 11 and the rack gear 50 in the axial direction.

Specifically, the plate-like portion 41 is disposed in a recess 11B formed on the outer surface of the side wall 11A. Thereby, the outer surface of the plate-shaped part 41 and the outer surface of the side wall 11A are substantially flush (see FIG. 7).

The first bearing portion 42 is a cylindrical portion that rotatably supports the shaft 12A of the developing roller 12. The first bearing portion 42 protrudes from the plate-like portion 41 in the direction away from the housing 11 in the axial direction. Specifically, the first bearing portion 42 protrudes in a direction away from the housing 11 in the axial direction than the second bearing portion 43.

The second bearing portion 43 is a cylindrical portion that rotatably supports the shaft 15A of the supply roller 15. The second bearing portion 43 protrudes from the plate-like portion 41 in the direction away from the housing 11 in the axial direction. The second bearing portion 43 is disposed closer to the agitator gear 31 than the first bearing portion 42.

The 1st guide part 44 is a part which supports the rack gear 50 so that a movement to the direction which goes to the other end E20 from the one end E10 of the housing | casing 11 mentioned later is possible. The first guide portions 44 are provided one by one so as to sandwich the rack gear 50 therebetween. Each first guide portion 44 supports the rack gear 50. Each first guide portion 44 protrudes from the plate-like portion 41 in the direction away from the housing 11 in the axial direction. Each of the first guide portions 44 is formed in a plate shape orthogonal to the plate-like portion 41, and the width in the direction from the one end E10 to the other end E20 of the housing 11 is larger than the width in the axial direction. Each first guide portion 44 is disposed closer to the agitator gear 31 than the second bearing portion 43.

The housing 11 has a second guide portion 11C, a third guide portion 11D, and a fourth guide portion 11E that support the rack gear 50 so as to be movable in a direction from one end E10 to the other end E20 of the housing 11. The second guide portion 11C is disposed on the opposite side of the rack gear 50 from the third guide portion 11D and the fourth guide portion 11E. The second guide portion 11C extends from the third guide portion 11D to the fourth guide portion 11E in a direction from one end E10 to the other end E20 of the housing 11.

The third guide portion 11D and the fourth guide portion 11E face the surface of the rack gear 50 that faces the agitator gear 31. The third guide portion 11 D is disposed on the developing roller 12 side with respect to the agitator gear 31. The fourth guide portion 11E is disposed on the opposite side of the agitator gear 31 from the third guide portion 11D in the direction from the one end E10 to the other end E20 of the housing 11.

The rack gear 50 is movable in a direction from one end E10 of the housing 11 to the other end E20 opposite to the one end E10. The rack gear 50 includes a main body 51, a rack gear 52, and a first protrusion 53 and a second protrusion 54 as examples of protrusions. The main body 51 has a rectangular plate shape that is long in the direction from the one end E10 to the other end E20 of the housing 11. The rack gear portion 52 has a plurality of gear teeth that mesh with the agitator gear 31. The main body 51 extends in the moving direction of the rack gear 50. The rack gear portion 52 and the

protrusions

53 and 54 protrude from the surface of the main body portion 51 that faces the agitator gear 31. The rack gear 50 is configured to move in a direction from one end E10 of the housing 11 to the other end E20 only while the rack gear portion 52 is engaged with the agitator gear 31. The rack gear 50 is configured to stop when the rack gear portion 52 is disengaged from the agitator gear 31. That is, the rack gear 50 is movable in the direction from the one end E10 to the other end E20 as the agitator gear 31 rotates.

The rack gear portion 52 is disposed at a portion on the downstream side in the moving direction of the rack gear 50 in the end portion on the side close to the housing 11 in the axial direction of the main body portion 51. Specifically, the rack gear portion 52 is formed from the end portion close to the agitator gear 31 in the moving direction of the main body portion 51 to the central portion in the moving direction (see FIG. 4).

The first protrusion 53 and the second protrusion 54 are arranged at positions different from the rack gear portion 52 in the moving direction of the rack gear 50. The first protrusion 53 and the second protrusion 54 are disposed at positions different from the rack gear portion 52 in the axial direction. Specifically, the first protrusion 53 and the second protrusion 54 are arranged at a position farther from the housing 11 than the rack gear part 52 in the axial direction of the main body part 51. The first protrusion 53 and the second protrusion 54 are disposed closer to the developing roller 12 than the rack gear portion 52 in the movement direction of the rack gear 50. More specifically, the first protrusion 53 is disposed in the vicinity of the central portion in the movement direction of the main body 51. The second protrusion 54 is disposed at an end portion close to the developing roller 12 in the moving direction of the main body portion 51. The first protrusion 53 and the second protrusion 54 can come into contact with a first cam surface 73A or a third cam surface 74A (see FIG. 6) of the cam 70 described later by the movement of the rack gear 50.

The gear cover 60 covers the agitator gear 31 and the rack gear 50. As shown in FIG. 5, the gear cover 60 covers the cam 70, the developing electrode 20, and a compression coil spring SP as an example of a spring. The cam 70 moves in the axial direction by receiving a force from the rack gear 50. The cam 70 is made of non-conductive resin. The compression coil spring SP is made of a conductive material, specifically a metal.

The gear cover 60 includes a first cover portion 61 that covers the rack gear 50 and the agitator gear 31, a second cover portion 62 that covers the cam 70 and the developing electrode 20, and a third cover portion 63 that covers the compression coil spring SP. . The first cover portion 61 is formed to extend long in the direction from the one end E10 of the housing 11 to the other end E20 so as to cover the rack gear 50 before and after movement.

The second cover portion 62 protrudes in a direction away from the housing 11 in the axial direction from a substantially central portion in the direction from the one end E10 to the other end E20 of the housing 11 of the first cover portion 61. The inside of the second cover part 62 communicates with the inside of the first cover part 61. The second cover portion 62 has an opening 62A that exposes the developing electrode 20 to the outside.

The third cover part 63 has a through hole 63A penetrating in the axial direction. The compression coil spring SP is disposed inside the through hole 63A. The third cover portion 63 is disposed at substantially the same position as the second cover portion 62 in the direction from the one end E10 to the other end E20 of the housing 11. The third cover part 63 protrudes in a direction away from the rack gear 50 from the first cover part 61. The through hole 63A opens toward the developing electrode 20.

In the present embodiment, the hollow portion is provided by removing the space between the outer peripheral surface of the third cover portion 63 and the through hole 63A, but the present invention is not limited to this, and the third cover portion 63 A hollow portion may not be provided between the outer peripheral surface and the through hole 63A.

The cam 70 is supported by the second cover portion 62 of the gear cover 60 so as to be movable in the axial direction. The cam 70 is movable between a first position shown in FIG. 8A and a second position shown in FIG. 8B. The second position is farther from the housing 11 than the first position in the axial direction. As shown in FIG. 6, the cam 70 includes a base portion 71, a rib 72, a first cam portion 73, a third cam portion 74, a protruding portion 75, and two second cam portions 76. ing.

The base portion 71 is a plate-like portion orthogonal to the direction in which the rack gear 50 and the cam 70 face each other. The base portion 71 has a length in the axial direction larger than a width in a direction from the one end E10 to the other end E20 of the housing 11. The rib 72 protrudes toward the rack gear 50 from the end portion of the base portion 71 on the side close to the housing 11.

The first cam portion 73 and the third cam portion 74 are disposed between the rib 72 and the protruding portion 75. The first cam portion 73 and the third cam portion 74 protrude from the base portion 71 toward the rack gear 50.

The first cam portion 73 is disposed at a position different from the third cam portion 74 in the movement direction of the rack gear 50. Specifically, the first cam portion 73 is disposed at a position farther from the agitator gear 31 in the movement direction of the rack gear 50 than the third cam portion 74. The first cam portion 73 extends obliquely from the protruding portion 75 toward the rib 72 side and the downstream side in the moving direction of the rack gear 50. The first cam portion 73 has one end connected to the projecting portion 75 and the other end separated from the rib 72. The distance between the other end of the first cam portion 73 and the rib 72 is larger than the diameter of each

projection

53, 54 of the rack gear 50.

The first cam portion 73 has a first cam surface 73A that is inclined with respect to the moving direction of the rack gear 50. The first cam surface 73A is a surface for moving the cam 70 in the direction away from the housing 11 in the axial direction. The first cam surface 73A can come into contact with the

protrusions

53 and 54 of the rack gear 50 when the cam 70 is located at the first position. The first cam surface 73A moves the cam 70 from the first position to the second position by moving the rack gear 50 in the direction from the one end E10 to the other end E20 while in contact with the first protrusion 53 or the second protrusion 54. To move. In other words, the first cam surface 73A is movable from the first position to the second position outside the movement locus of the

protrusions

53, 54 by engaging with the

protrusions

53, 54.

The first cam surface 73A is inclined so as to approach the casing 11 in the axial direction toward the downstream side in the movement direction of the rack gear 50. Specifically, the first cam surface 73A includes a first end E1 and a second end E2 that is located farther from the housing 11 than the first end E1 in the axial direction. The first cam surface 73A is inclined such that the first end E1 is located downstream of the second end E2 in the movement direction of the rack gear 50.

The third cam portion 74 extends obliquely from the approximate center of the rib 72 in the direction from the one end E10 to the other end E20 of the casing 11 toward the protruding portion 75 side and the downstream side in the moving direction of the rack gear 50. The third cam portion 74 has one end connected to the rib 72 and the other end separated from the protruding portion 75. The distance between the other end of the third cam portion 74 and the protruding portion 75 is larger than the diameters of the

protrusions

53 and 54 of the rack gear 50.

The third cam portion 74 has a third cam surface 74A that is inclined with respect to the moving direction of the rack gear 50. The third cam surface 74A is a surface for moving the cam 70 in a direction approaching the housing 11 in the axial direction. The third cam surface 74A can come into contact with the

protrusions

53 and 54 of the rack gear 50 when the cam 70 is located at the second position. In other words, the third cam surface 74A is disposed on the movement locus of the

protrusions

53 and 54 when the cam 70 is located at the second position. The third cam surface 74A moves the cam 70 from the second position to the first position by moving the rack gear 50 in the direction from the one end E10 toward the other end E20 while in contact with the first protrusion 53 or the second protrusion 54. Move towards.

The third cam surface 74A is disposed downstream of the first cam surface 73A in the movement direction of the rack gear 50. The third cam surface 74A is disposed at a position different from the first cam surface 73A in the moving direction of the cam 70. Specifically, the first cam surface 73A is disposed at a position farther from the housing 11 than the third cam surface 74A in the axial direction.

The third cam surface 74A is inclined so as to be separated from the housing 11 in the axial direction as it goes downstream in the moving direction of the rack gear 50. Specifically, the third cam surface 74A has a third end E3 and a fourth end E4 that is located farther from the housing 11 than the third end E3 in the axial direction. The third cam surface 74A is inclined so that the fourth end E4 is located downstream of the third end E3 in the movement direction of the rack gear 50.

The protruding portion 75 protrudes toward the developing electrode 20 from a portion of the base portion 71 far from the housing 11. The protruding portion 75 is formed from the end portion of the base portion 71 on the side far from the housing 11 to the first cam portion 73. The protrusion 75 has a rectangular through hole 75B that penetrates in the axial direction.

Each second cam portion 76 protrudes toward the developing electrode 20 from a surface of the protruding portion 75 facing the developing electrode 20 (hereinafter also referred to as “first surface 75A”). The second cam portions 76 are arranged with an interval in the axial direction. Each of the second cam portions 76 is disposed away from one end and the other end of the protruding portion 75 in the axial direction. Each second cam portion 76 has a second cam surface 76A that is inclined with respect to the axial direction, and a holding surface 76B that supports the developing electrode 20.

The second cam surface 76A moves in contact with the developing electrode 20 when the cam 70 moves from the first position to the second position, so that the movement direction of the rack gear 50 and the movement direction of the cam 70 are different. 3 is a surface for moving the developing electrode 20 away from the cam 70. The second cam surface 76A is movable together with the first cam surface 73A. The second cam surface 76A is disposed at a position farther from the housing 11 than the first cam surface 73A in the axial direction.

The second cam surface 76A is inclined so as to approach the first surface 75A as it goes away from the housing 11 in the axial direction. Specifically, the second cam surface 76A has a fifth end E5 and a sixth end E6 that is further away from the housing 11 than the fifth end E5 in the axial direction. The second cam surface 76A is inclined so as to protrude toward the developing electrode 20 from the sixth end E6 toward the fifth end E5. In other words, the second cam surface 76A is inclined so as to protrude toward the opening 62A from the sixth end E6 toward the fifth end E5. The holding surface 76B extends along the first surface 75A.

Returning to FIG. 5, the developing electrode 20 is movably supported by the second cover portion 62 of the gear cover 60. The developing electrode 20 is provided on the first surface 75 A of the cam 70. The developing electrode 20 is movable between a third position and a fourth position farther from the cam 70 than the third position. The developing electrode 20 includes a substantially rectangular parallelepiped electrode portion 21, a first flange portion 22 that protrudes in a direction away from the electrode portion 21 in the axial direction from an end portion of the electrode portion 21 opposite to a second surface 21A, which will be described later. And a second flange portion 23.

The electrode portion 21 is disposed so as to protrude from the opening 62A of the second cover portion 62 in a direction away from the cam 70 (see FIG. 3). Specifically, the protruding amount of the electrode portion 21 from the opening 62A is larger when the developing electrode 20 is positioned at the fourth position than when the developing electrode 20 is positioned at the third position.

The surface of the electrode portion 21 opposite to the surface facing the cam 70 (hereinafter also referred to as “second surface 21 A”) has an arc shape that is convex in a direction away from the cam 70 in a cross section orthogonal to the axial direction. It is a curved surface. The electrode portion 21 has two concave portions 24 into which the second cam portions 76 of the cam 70 can enter. The recess 24 is formed so as to be recessed in a direction away from the cam 70 from the surface of the electrode portion 21 facing the cam 70. The recess 24 has a fourth cam surface 24A that contacts the second cam surface 76A of the second cam portion 76, and a bottom surface 24B that extends along the first surface 75A. The fourth cam surface 24A extends along the second cam surface 76A.

Of the surfaces facing the cam 70 of the electrode portion 21, the surface located between the two recesses 24 is the second cam on the side close to the housing 11 of the cam 70 when the developing electrode 20 is located at the fourth position. It is a supported surface 21 B supported by the portion 76. The surface of the first flange portion 22 that faces the cam 70 is a supported surface that is supported by the second cam portion 76 on the side far from the housing 11 of the cam 70 when the developing electrode 20 is located at the fourth position. 22A. When the developing electrode 20 is located at the third position, at least one of the surface of the developing electrode 20 facing the cam 70 (the surface including the supported

surfaces

21B and 22A) and the bottom surface 24B of each recess 24 is a cam. 70 may be supported.

7, the compression coil spring SP is disposed between the electrode portion 21 of the developing electrode 20 and the plate-like portion 41 of the bearing 40 in the axial direction. Specifically, one end of the compression coil spring SP is in contact with the electrode portion 21 of the developing electrode 20, and the other end opposite to the one end of the compression coil spring SP is in contact with the plate-like portion 41 of the bearing 40. Thereby, the developing electrode 20 is electrically connected to the developing roller 12 and the supply roller 15 via the compression coil spring SP and the bearing 40.

More specifically, the compression coil spring SP is in contact with the surface of the electrode portion 21 closer to the casing 11. Thereby, the compression coil spring SP is used when the developing electrode 20 is located at the third position, when the developing electrode 20 is moved from the third position to the fourth position, and when the developing electrode 20 is located at the fourth position. In contact with the electrode portion 21. That is, the developing electrode 20 can be moved in contact with the compression coil spring SP.

The compression coil spring SP is shorter than the natural length in a state where one end of the compression coil spring SP is in contact with the developing electrode 20 and the other end of the compression coil spring SP is in contact with the bearing 40. Further, the compression coil spring SP is disposed on the opposite side of the rack gear 50 from the cam 70. The compression coil spring SP is disposed between the first guide portion 44 and the second guide portion 11C in the direction from the one end E10 to the other end E20 of the housing 11.

Next, the function and effect of each member constituting the developing cartridge 1 will be described in detail. When the developing cartridge 1 is in a new state, the rack gear 50 is positioned closest to the end E10 of the casing 11, and the cam 70 is positioned closest to the casing 11 so that the developing electrode 20 is positioned. Is in the third position.

As shown in FIG. 2, when the development cartridge 1 in a new state is mounted on the main body housing, the second surface 21A of the development electrode 20 comes into contact with the electrode provided on the actuator AC. As a result, a developing bias is supplied to the developing electrode 20 from the power source (not shown) of the image forming apparatus via the electrode of the actuator AC.

Thereafter, when a driving force is input to the coupling 13 of the developing cartridge 1 from a driving source (not shown) of the main body housing, the driving force is transmitted to the shaft 14A of the agitator 14 via the coupling 13 and the gear mechanism. The driving force transmitted to the shaft 14A of the agitator 14 is transmitted to the agitator gear 31 as shown in FIG.

When the agitator gear 31 to which the driving force is transmitted rotates, the rack gear 50 moves in the direction from the one end E10 of the housing 11 to the other end E20. Due to the movement of the rack gear 50, the first protrusion 53 of the rack gear 50 abuts on the first cam surface 73A of the cam 70 as shown in the order of FIGS. When pressed, the cam 70 moves in a direction away from the housing 11 in the axial direction. 8A to 8D, a portion indicated by hatching of dots indicates a portion of the agitator gear 31 that can mesh with the rack gear portion 52.

When the cam 70 moves in the direction away from the housing 11 in the axial direction, as shown in the order of FIGS. 9A and 9B, the developing electrode 20 is pushed up by the second cam surfaces 76A of the cam 70, The developing electrode 20 moves from the third position to the fourth position. That is, the developing electrode 20 moves in a direction away from the cam 70 by receiving a force from the cam 70 moving in the direction away from the housing 11 in the axial direction.

When the developing electrode 20 moves to the fourth position, the actuator AC is pushed up by the developing electrode 20 and displaced. That is, the cam 70 applies a force to the actuator AC via the developing electrode 20 to displace the actuator AC in one direction. Thereby, the optical sensor detects displacement in one direction of the actuator AC. The control device of the image forming apparatus can determine that the developing cartridge 1 is new when the optical sensor detects the displacement of the actuator AC.

As shown in the order of FIGS. 8B and 8C, when the rack gear 50 further moves in the direction from the one end E 10 to the other end E 20 of the housing 11, the first protrusion 53 of the rack gear 50 causes the third projection of the cam 70. Since the cam surface 74A is pressed, the cam 70 moves in a direction approaching the housing 11 in the axial direction. Accordingly, as shown in the order of FIGS. 9B and 9A, the holding surfaces 76 B of the cam 70 are separated from the supported surfaces 21 B and 22 A of the developing electrode 20, and the developing electrode 20 is in the fourth position. To the third position. The movement of the developing electrode 20 from the fourth position to the third position may be performed by gravity or may be performed by a spring that biases the actuator AC.

Thereafter, as shown in the order of FIGS. 8C and 8D, when the rack gear 50 further moves in the direction from the one end E 10 to the other end E 20 of the housing 11, the second protrusion 54 of the rack gear 50 is moved to the cam 70. By sequentially pressing the cam surfaces 73A and 74A, the cam 70 moves in a direction away from the housing 11 in the axial direction, and then moves in a direction approaching the housing 11 in the axial direction. Thereby, after the developing electrode 20 moves again to the fourth position and then returns to the third position, the optical sensor detects the displacement of the actuator AC in one direction. That is, in this embodiment, the optical sensor detects the displacement of the actuator in one direction twice after the new developing cartridge 1 is mounted on the main body housing. This corresponds to the number of

protrusions

53 and 54 provided on the rack gear 50. For example, when only one protrusion is provided, the number of displacements in one direction of the actuator detected by the optical sensor is one. Therefore, the control device can also determine the specifications of the developing cartridge 1 by setting the number of protrusions provided on the rack gear 50 according to the specifications of the developing cartridge 1 (for example, the difference in the amount of toner accommodated).

As shown in FIG. 8D, when the second protrusion 54 is detached from the third cam surface 74A, the rack gear 50 is then detached from the agitator gear 31. As a result, transmission of the driving force from the agitator gear 31 to the rack gear 50 is cut off, and the developing electrode 20 is held in the third position.

According to the above, the following effects can be obtained in the present embodiment.
As the rack gear 50 moves in the direction from the one end E10 to the other end E20 of the housing 11, the rack gear 50 and the agitator gear 31 can be disengaged.

Since the developing electrode 20 is formed of a conductive resin, the shape of the developing electrode 20 can be easily formed.

The present invention is not limited to the first embodiment, and can be used in various forms as exemplified below. In the following description, the same reference numerals are given to members having substantially the same structure as in the above embodiment, and the description thereof is omitted.

[Second Embodiment]
As shown in FIG. 10, in the developing cartridge 101 of the second embodiment, the spring (compression coil spring SP) and the developing electrode 20 that are configured as separate parts in the first embodiment are integrally configured. Specifically, the developing cartridge 101 of the second embodiment includes a housing 11, an agitator gear 31, and a bearing 40 similar to those of the first embodiment, and a rack gear 150 and a cam that are different from those of the first embodiment. 170 and a spring electrode 80. As shown in FIG. 11A, the cam 170 has a base portion 71 and a protruding portion 75 that are the same as those in the first embodiment, and has a protrusion 77 and a spring support portion 78 that are not in the first embodiment. is doing.

The protrusion 77 protrudes toward the spring electrode 80 from the end portion of the base portion 71 on the side close to the housing 11. The protrusion 77 is formed in a semi-cylindrical shape. The surface of the protrusion 77 far from the housing 11 is an arcuate curved surface that is convex in a direction away from the housing 11 in the axial direction.

The spring support portion 78 protrudes from the first surface 75A of the protrusion 75 toward the spring electrode 80. The surface of the spring support portion 78 that faces the spring electrode 80 has a first plane 78A and a second plane 78B that extend along the base portion 71, and an inclined surface 78C that connects the first plane 78A and the second plane 78B. ing. The first plane 78A is disposed at a position farther from the base portion 71 than the second plane 78B. The first plane 78A is disposed closer to the housing 11 than the second plane 78B. The inclined surface 78C is inclined so as to approach the base portion 71 in the axial direction from the edge farther from the housing 11 of the first plane 78A toward the direction away from the housing 11, and the housing of the second plane 78B. 11 is connected to the edge near the side.

A concave portion 78D that is recessed toward the base portion 71 is formed at the center of each surface 78A to 78C in the direction from the one end E10 to the other end E20 of the casing 11. The concave portion 78D is formed continuously from the end edge of the first plane 78A near the casing 11 to the end edge of the second plane 78B far from the casing 11. Further, an engaging claw 78F protruding from the side surface 78E is formed on a side surface 78E of the spring support portion 78 on the side close to the housing 11.

The through hole 63A of the third cover part 63 of the gear cover 60 is formed in a size corresponding to the spring electrode 80.

The spring electrode 80 is made of a conductive material. The spring electrode 80 is electrically connected to the developing roller 12. The spring electrode 80 can move together with the cam 170. The spring electrode 80 includes a developing electrode 81 having a shape following the shape of the spring support portion 78 and a spring 82 formed integrally with the developing electrode 81. The developing electrode 81 includes a first plate-like portion 81A and a second plate-like portion 81B that extend along the base portion 71, and a third plate-like portion 81C that connects the first plate-like portion 81A and the second plate-like portion 81B. From the end of the first plate-like part 81A on the side close to the casing 11, the fourth plate-like part 81D extending toward the base part 71 and the end of the second plate-like part 81B on the side far from the casing 11 A fifth plate-like portion 81 E extending toward the base portion 71.

The first plate-like portion 81A, the second plate-like portion 81B, and the third plate-like portion 81C enter the recess 78D of the spring support portion 78 and are supported by the bottom surface of the recess 78D. In a state where the plate-like portions 81A to 81C are supported by the bottom surface of the recess 78D, the surface of the plate-like portions 81A to 81C opposite to the surface facing the cam 170 is opposite to the base portion 71 of the spring support portion 78. It is located at a position farther from the base portion 71 than the surface on the opposite side to the base portion 71 of the spring support portion 78 or flush with the side surface. And the surface on the opposite side to the cam 170 of the 3rd plate-shaped part 81C inclined with respect to the axial direction is the 2nd cam surface 81G.

The second cam surface 81G has a fifth end E105 and a sixth end E106 that is farther from the housing 11 than the fifth end E5 in the axial direction. The second cam surface 81G is inclined so as to protrude toward the opening 62A from the sixth end E6 toward the fifth end E5.

The fourth plate portion 81D and the fifth plate portion 81E sandwich the spring support portion 78 in the axial direction. The fourth plate-shaped portion 81D is formed with an engagement hole 81F that engages with the engagement claw 78F of the spring support portion 78.

The spring 82 includes a flat plate-like portion 82A extending along the first plate-like portion 81A, a first curved portion 82B curved so as to be convex toward the opposite side of the cam 170, and a convex toward the housing 11. The second bending portion 82C is curved so as to be. The flat plate-like portion 82A extends from the end of the fourth plate-like portion 81D on the cam 170 side toward the housing 11. The first curved portion 82B is connected to the end portion of the flat plate-like portion 82A on the side close to the housing 11. The second bending portion 82C extends from the end of the first bending portion 82B on the side close to the housing 11 toward the side opposite to the cam 170.

The spring 82 is disposed between the side surface 78E of the spring support portion 78 and the bearing 40 as shown in FIG. The end of the spring 82 on the side close to the housing 11 is in contact with the bearing 40. The spring 82 urges the cam 170 in a direction away from the housing 11 in the axial direction in a state where the cam 170 is located at the initial position (position shown in FIG. 13A). That is, the spring 82 biases the cam 170 from the initial position (an example of the first position) toward the outer position (an example of the second position).

As shown in FIG. 11B, the rack gear 150 has a structure having a main body portion 51 and a rack gear portion 52 similar to those in the first embodiment, and a cam portion 55 not in the first embodiment. ing. The cam portion 55 is disposed at an upstream portion in the moving direction of the rack gear 150 in the end portion far from the housing 11 in the axial direction of the main body portion 51. In the following description, “the upstream side in the movement direction of the rack gear” and “the downstream side in the movement direction of the rack gear” are also simply referred to as “upstream side” and “downstream side”, respectively.

The cam portion 55 protrudes from the main body portion 51. The surface of the cam portion 55 closer to the housing 11 is a flat first holding surface 55A, second holding surface 55B and third holding surface 55C orthogonal to the axial direction, and the first holding surface 55A and the second holding surface. It has a connecting surface 55D that connects the surface 55B, and a cam surface 55E that connects the second holding surface 55B and the third holding surface 55C.

The first holding surface 55A and the third holding surface 55C are arranged at the same position in the axial direction. The first holding surface 55A is disposed downstream of the third holding surface 55C. The first holding surface 55A and the third holding surface 55C come into contact with the protrusion 77 to hold the cam 170 at the initial position (first position).

The second holding surface 55B is disposed between the first holding surface 55A and the third holding surface 55C in the moving direction of the rack gear 150. The second holding surface 55B is disposed at a position farther from the housing 11 than the first holding surface 55A (see FIG. 12A). The second holding surface 55B comes into contact with the protrusion 77 and holds the cam 170 at the outer position (second position).

The connecting surface 55D is inclined so as to be positioned away from the housing 11 in the axial direction from the upstream end edge of the first holding surface 55A toward the upstream side, and the downstream end of the second holding surface 55B. It is connected to the edge. The cam surface 55E is inclined with respect to the moving direction of the rack gear 150. Specifically, the cam surface 55E is inclined so as to approach the housing 11 from the upstream edge of the second holding surface 55B toward the upstream side, and is connected to the downstream edge of the third holding surface 55C. Yes.

In this embodiment, as shown in FIG. 12A, when the developing cartridge 1 is in a new state, the projection 77 of the cam 170 is supported by the first holding surface 55A of the rack gear 150, so that the cam 170 is in the initial position. Located in. Specifically, the urging force applied from the spring electrode 80 to the cam 170 is received by the first holding surface 55A.

When the developing cartridge 1 is attached to the main body housing with the cam 170 positioned at the initial position, the second plate-like portion 81B of the spring electrode 80 supported by the cam 170 is mounted as shown in FIG. Thus, the actuator AC is pushed. As a result, the actuator AC swings from the first posture to the second posture. The optical sensor detects the displacement of the actuator AC. At this time, the electrode of the actuator AC and the spring electrode 80 are electrically connected.

Then, as shown in the order of FIGS. 12A and 12B, when the driving force is transmitted to the agitator gear 31, the rack gear 150 moves in the direction from one end E10 of the housing 11 toward the other end E20. When the first holding surface 55 A comes off the projection 77 due to the movement of the rack gear 150, the cam 170 moves in the direction away from the housing 11 in the axial direction by the biasing force of the spring electrode 80. Thereafter, when the protrusion 77 contacts the second holding surface 55B, the movement of the cam 170 is stopped, and the cam 170 is positioned at an outer position farther from the housing 11 than the initial position.

During the movement of the cam 170 from the initial position to the outer position, the actuator AC is pushed by the inclined third plate-like portion 81C of the spring electrode 80 supported by the cam 170, as shown in FIG. As a result, the actuator AC swings from the second posture to the third posture, and the optical sensor detects the displacement of the actuator AC.

Thereafter, as shown in the order of FIGS. 12B and 12C, when the rack gear 150 further moves in the direction from the one end E10 to the other end E20 of the housing 11, the projection 77 is pivoted by the cam surface 55E of the rack gear 150. When the cam 170 is pushed against the biasing force of the spring electrode 80 in the direction approaching the housing 11 in the direction, the cam 170 returns from the outer position to the initial position. As a result, as shown in FIG. 13A, the actuator AC swings from the third posture to the second posture, and the optical sensor detects the displacement of the actuator AC.

As described above, in the second embodiment, as in the first embodiment, the rack gear 150 moves in the direction from the one end E10 to the other end E20 of the housing 11 so that the rack gear 150 and the agitator gear 31 are engaged. Can be removed. In the second embodiment, since the spring 82 and the developing electrode 81 are configured as one component (spring electrode 80), the number of components can be reduced. The spring and the developing electrode may be separate parts. The spring as a separate part may be a coil spring or a wire spring.

In the first embodiment, the development electrode 20 is provided with the fourth cam surface 24A, and the cam 70 is provided with the second cam surface 76A. However, the present invention is not limited to this. A protrusion that engages with the two cam surfaces may be provided.

In the first embodiment, the entire rack gear 50 is covered with the gear cover 60. However, the present invention is not limited to this, and the gear cover may cover a part of the rack gear and expose the other part to the outside. .

In the above embodiment, the agitator gear 31 is exemplified as an example of the gear, but the present invention is not limited to this, and other gears may be used.

In the above embodiment, the compression coil spring SP and the spring 82 are exemplified as the spring, but the present invention is not limited to this, and may be, for example, a wire spring or a torsion spring.

In the first embodiment, the cam 70 is supported by the gear cover 60 so as to be movable. However, the present invention is not limited to this, and the cam may be supported by the housing so as to be movable.

Further, the elements described in the above-described embodiments and modifications may be implemented in any combination.

DESCRIPTION OF SYMBOLS 1 Developing cartridge 11 Housing | casing 12 Developing roller 20 Developing electrode 31 Agitator gear 50

Rack gear

53, 54 Protrusion 70 Cam 73A First cam surface 76A Second cam surface

Claims

A housing that can accommodate toner inside;
A developing roller rotatable about a first axis extending in the axial direction, the developing roller located at one end of the housing;
A developing electrode electrically connected to the developing roller;
A gear rotatable about a second axis along the first axis;
A rack gear meshing with the gear, the rack gear movable in a direction from one end of the housing toward the other end opposite to the one end, and a rack gear having a protrusion;
A cam movable from a first position to a second position farther from the housing than the first position in the axial direction;
A first cam surface that contacts the protrusion at the first position, and the rack gear moves in a direction from the one end toward the other end while being in contact with the protrusion, thereby moving the cam to the second position. A first cam surface that moves toward the
When the cam is moved from the first position to the second position, the developing electrode is moved in contact with the developing electrode so that the developing electrode is moved in a direction different from the moving direction of the rack gear and the moving direction of the cam. A developing cartridge comprising: a cam having a second cam surface that moves in a direction away from the cam.
The developing cartridge according to claim 1, further comprising a spring for electrically connecting the developing electrode and the developing roller.
A bearing for supporting the developing roller;
One end of the spring is in contact with the developing electrode,
The developing cartridge according to claim 2, wherein the other end of the spring opposite to the one end is in contact with the bearing.
4. The developing cartridge according to claim 3, wherein the spring is shorter than a natural length in a state where one end of the spring is in contact with the developing electrode and the other end of the spring is in contact with the bearing. .
5. The developing cartridge according to claim 3, wherein the bearing is formed of a conductive resin.
The developing cartridge according to any one of claims 1 to 5, wherein the developing electrode is formed of a conductive resin.
The first cam surface is
A first end;
A second end located at a position farther from the housing than the first end in the axial direction;
The said 1st cam surface is inclined so that the said 1st end part may be located in the movement direction of the said rack gear rather than the said 2nd end part. 2. A developing cartridge according to item 1.
The cam is a third cam surface disposed downstream of the first cam surface in the movement direction of the rack gear, and is in contact with the protrusion when the cam is positioned at the second position. Have
The said 3rd cam surface moves the said cam from the said 2nd position toward the said 1st position by the said rack gear moving in the state which contacted the said protrusion, The Claim 1 characterized by the above-mentioned. 8. The developing cartridge according to any one of 7 above.
The third cam surface is
A third end;
A fourth end located at a position farther from the housing than the third end in the axial direction;
The developing cartridge according to claim 8, wherein the third cam surface is inclined so that the fourth end portion is located downstream of the third end portion in the movement direction of the rack gear.
10. The developing cartridge according to claim 8, wherein the first cam surface is disposed at a position different from the third cam surface in the moving direction of the cam.
An agitator for stirring the toner inside the housing;
An agitator gear supported at an end of the agitator and rotatable together with the agitator,
The developing cartridge according to claim 1, wherein the agitator gear is the gear.
The developing cartridge according to any one of claims 1 to 11, further comprising a coupling disposed on the opposite side of the developing electrode with the casing interposed therebetween.
13. The development according to claim 1, wherein the development electrode has a fourth cam surface that contacts the second cam surface and extends along the second cam surface. cartridge.
The rack gear has a plate-like main body extending in the moving direction of the rack gear, and a plurality of gear teeth meshing with the gear,
The plurality of gear teeth and the protrusion protrude from the main body and are arranged at different positions in the movement direction of the rack gear. Developer cartridge.
The developing cartridge according to claim 1, wherein the protrusion is disposed at a position different from the plurality of gear teeth in the axial direction.
The second cam surface has a fifth end portion and a sixth end portion that is farther from the housing than the fifth end portion in the axial direction, and the sixth end portion to the fifth end portion. The developing cartridge according to claim 1, wherein the developing cartridge is inclined so as to protrude toward the developing electrode as it goes toward the developing electrode.
A housing for storing toner inside,
A developing roller rotatable about a first axis extending in the axial direction, the developing roller located at one end of the housing;
A gear rotatable about a second axis extending in the axial direction;
A developing electrode electrically connected to the developing roller;
The rack gear is movable in a direction from the one end toward the other end opposite to the one end, and is a rack gear that meshes with the gear and is movable in the direction from the one end toward the other end when the gear rotates. A rack gear having a protrusion,
A cover covering at least a part of the rack gear, the cover having an opening exposing the developing electrode;
A cam that is movable to a first position and a second position that is further away from the housing in the axial direction than the first position;
A first cam surface having a first end and a second end farther from the housing than the first end in the axial direction, wherein the first end is more than the second end. Is a first cam surface inclined so as to be located downstream in the movement direction of the protrusion, and can be moved from the first position to the second position outside the movement locus of the protrusion by engaging with the protrusion. A first cam surface,
A second cam surface movable together with the first cam surface, the second cam surface being disposed at a position farther from the housing than the first cam surface in the axial direction, and the developing electrode A second cam surface movable in contact with the second cam surface, the fifth cam surface having a fifth end and a sixth end farther from the housing than the fifth end in the axial direction. A developing cartridge comprising: a cam having a second cam surface that inclines so as to protrude toward the opening from the sixth end portion toward the fifth end portion.
The developing cartridge according to claim 17, further comprising a spring for electrically connecting the developing electrode and the developing roller.
The cam is a third cam surface arranged downstream of the first cam surface in the movement direction of the rack gear, and is arranged on a movement locus of the protrusion when the cam is located at the second position. A third cam surface
The third cam surface is
A third end;
A fourth end located at a position farther from the housing than the third end in the axial direction;
19. The developing cartridge according to claim 17, wherein the third cam surface is inclined so that the fourth end portion is located downstream of the third end portion in the movement direction of the rack gear.
A housing for storing toner inside,
A developing roller rotatable about a first axis extending in the axial direction, the developing roller located at one end of the housing;
A gear rotatable about a second axis along the axial direction;
A rack gear meshing with the gear, the rack gear movable in a direction from one end of the housing toward the other end opposite to the one end;
A cam that is movable from a first position to a second position that is farther from the housing than the first position in the axial direction;
A spring that biases the cam from the first position toward the second position;
A cover having an opening;
A developing electrode electrically connected to the developing roller, the developing electrode being movable together with the cam, and having a fifth end portion and being separated from the casing more than the fifth end portion in the axial direction. A second cam surface having a sixth end portion and a second cam surface inclined to protrude toward the opening from the sixth end portion toward the fifth end portion; With
The rack gear has a first holding surface that contacts the protrusion and holds the cam in the first position, and a second holding surface that contacts the protrusion and holds the cam in the second position. A developing cartridge characterized by the above.
The developing cartridge according to claim 20, wherein the developing electrode is formed integrally with the spring.